Some Schooling On Backpacks

By Ian K. Smith, M.D.

Like many kids now heading back to school, I used one of those fashionable single-strap, over-the-shoulder bags to carry my books around when I was studying in New York City. But at Dartmouth Medical School, my city bag turned out to be totally inadequate for lugging heavy medical texts. I'd lose valuable minutes at the start of a lecture rubbing an aching arm and shoulder before I could start writing down what the prof said. Taking a cue from classmates, I finally got a large, wide-strapped bag with a third strap that wrapped around the hips. It wasn't chic but it did wonders for my sore muscles--and note taking.

That was a first-hand lesson in how the wrong backpack, or carrying one improperly, can lead to serious problems. According to the U.S. Consumer Product Safety Commission, 5,900 kids were treated at hospital emergency rooms, clinics and doctors' offices last year for sprains and strains directly caused by backpacks. Indeed, such injuries are so widespread that more than 70% of physicians surveyed by the American Academy of Orthopedic Surgeons listed backpacks as a potential clinical problem for children, and 58% said they had treated patients for pain caused by heavy backpacks.

How to avoid such problems? Like my classmates, you can choose bags that have wide, padded straps and a belt. That will help transfer some of the weight from the back and shoulders to the hips. You should also tighten both straps firmly, so the pack rests about two inches above your waist. Also, remember to pack your bag with the heaviest items closest to your back and to bend both knees when you pick it up.

How much should you stuff into your pack? That depends on your size and strength, but the rule of thumb is not to exceed 20% of your body weight. So if a child weighs 100 lbs., the backpack and its load shouldn't be more than 20 lbs. This applies to adults as well. For smaller children, the percentage should be scaled down, depending on the child's size and weight. One hint: make frequent trips to your locker to exchange books between classes.

Those trendy backpacks with wheels let you pull the weight along the ground. But they have problems too. Many are larger than the average shoulder bag, so students are tempted to carry more than they would in a conventional pack. Also, roller bags often don't fit into a locker and, more important, in crowded halls they can lead to tripping and falls.

Whatever you use, 10 or 15 minutes of stretching and back strengthening (stomach crunches and holding the pushup position for 10 seconds, for example) is a good idea. At the very least, it will keep you free of the pain that marred my early months in med school.

See Dr. Ian on NBC's Today show. E-mail: ianmedical@aol.com